1. Field of the Invention.
This invention relates in general to certain new and useful improvements in an apparatus and method for controlling the opening and closing movements of a gate, and more particularly to an apparatus and method of the type stated which utilizes a drive arm and coupling arm arrangement for enabling automatic opening and closing of a gate which permits separation of the coupling arm and drive arm to permit manual opening and closing of the gate.
2. Brief Description of the Prior Art.
Over the years, a variety of types and styles of gates have been developed to provide security for such areas as parking structures and entrances and exits to residential and industrial property. These gates may take the form of sliding gates which move in or on a track, or swinging gates which are rotatably hinged to a fixed structure. Where large passageways are involved, gates may be provided in pairs which operate from opposite sides of the openings.
Many control systems have been developed to provide automatic control for the opening and closing of gates. These control systems include an electric motor operatively connected to the gate to control its movement. Typically, the motor is controlled by a switch in the vicinity of the gate which can only be operated by authorized personnel. For example, the switch may be in the form of a key switch which can only be operated by use of a conventional key or by a card key.
In most of the prior art gate opening and closing apparatus, a positive locking mechanism was provided to physically and automatically lock the gate when it reached the closed position. In this way, only authorized access to a controlled area was achieved. Many of these prior art positive locking mechanisms relied upon the use of a solenoid operated lock which included a locking pin on the gate capable of being inserted into an opening on a fixed structure at the gate closed position. However, in each case, the gate was automatically and positively locked when it reached the closed position.
The locking of the gate at the closed position, while effective to provide a measure of security, poses many problems to the occupants of the controlled area as well as to public officials. If for some reason, there is a malfunction of the gate operating mechanism, it automatically locks at the closed position and the occupants on the inside of the controlled area would not have egress through the access opening covered by the gate. Thus, some means to physically unlock the gate has to be provided. In addition, in the event of power failure which could arise, as a result of disruption from an electrical utility supplier or as a result of a fire, it is necessary for public officials to have access to the controlled or secured area. Thus, some fire departments and other health control officials require a special unlocking mechanism located at the exterior of the gate and which is confined in a locked box or similar secured area to which they have special access. Many fire departments or other health or other public officials require a special key for access to these locked boxes or secured containers.
Notwithstanding, there are also many occasions in which the authorized user of the gate desires manual opening and closing movement of the gate as opposed to the automatic opening and closing movement. In essentially all other prior art gate opening and closing apparatus, in order to afford some mechanical and manual movement of the gate, complex disassembly of the gate opening and closing apparatus is required. This usually includes a need for access to the drive housing for purposes of uncoupling one or more gears in the drive housing. Thus, disengaging the automatic drive from the gate opening and closing mechanism is a complex and time consuming procedure.
In addition to the above, each of the prior art locking mechanisms also use a complex gear structure for purposes of driving the gate between the open.RTM.d and closed positions. While these gear boxes are effective, they are noisy and consume a substantial amount of the power generated by the electric motor. Moreover, it is virtually impossible to push a gate against the action of the gear box in the event of a power failure.
U.S. Pat. No. 4,159,599, dated July 3, 1979 by Moscow K. Richmond for "Gate Opening and Closing Assembly" discloses a gate which is slidable between opened and closed positions and which uses a solenoid operated locking mechanism. U.S. Pat. No. 4,313,281, dated Feb. 2, 1982 by Moscow K. Richmond for "Gate Opening and Closing Apparatus and Method" also discloses a positive locking mechanism for use in locking a gate when it reaches a gate closed position. U.S. Pat. No. 4,330,958 by Moscow K. Richmond, dated May 25, 1982 for "Gate Opening and Closing Assembly With Automatic Locking Means" also discloses a gate opening and closing assembly with an automatic locking means for locking the gate when it reaches a closed position. U.S. Pat. No. 4,429,264, dated Jan. 31, 1984, by Moscow K. Richmond, for "System and Method For The Automatic Control Of Electrically Operable Gates" discloses a gate opening and closing mechanism which utilizes automatic control features and which also provides for manual operation.